1. Field of the Invention
A cement lining slinger head tachometer device to detect and display the speed of rotation of a slinger head when lining the inner surface of a pipe with cement.
2. Description of the Prior Art
A cement lining is added to the inside surface of iron pipe to protect the iron and to improve the flow characteristics of the pipe.
Problems arise when the slinger head does not spin at the proper speed necessary to evenly and uniformly apply the cement mixture. This can be due to wear over the course of normal use or improper adjustment.
U.S. Pat. No. 4,502,853 discloses a rotational speed sensor for sensing the rotational speed of an aluminum alloy rotor having a permanent magnet embedded therein.
U.S. Pat. No. 4,361,288 teaches a rotating speed detecting device comprising an annular permanent magnet attached to the rotary shaft of a spray painting device and a detecting head mounted on the housing of the spray painting device to measure the speed of rotation of the rotary shaft.
JP 62-25267 relates to a magnetic signal generator ring comprising a resin magnet embedded in the outer peripheral surface of the ring fabricated of synthetic resin to form the magnetic signal generator ring.
U.S. Pat. No. 5,697,559 shows a rotary atomizer including a speed sensing system mounted in the atomizer housing utilizing both magnetics and optics for accurately measuring the rotational speed of the air turbine motor in the presence of high electrostatic charge and RF fields from an internal power supply.
U.S. Pat. No. 4,936,507 shows a speed monitoring device for the rotary atomizer. A pair of permanent magnets are mounted at diametrically opposed locations on the turbine wheel. Although one magnet is sufficient to generate a speed signal, two or more magnets are typically utilized to maintain the balance of the turbine wheel. A pickup coil including a magnetic core is located adjacent the path of the magnet. The ends of the pickup coil are connected to opposite ends of a single loop of dielectrically insulated high voltage wire in a series loop. The high voltage wire extends through an aperture formed in the end cover and through the aperture formed in the manifold body. Each time one of the magnets passes the pickup coil, an electrical pulse is generated in the coil and conducted through the high voltage wire. The pulse is inductively coupled to the torodial coil and sensed by the speed monitoring device.
U.S. Pat. No. 3,719,168 comprises a system for dispensing and applying a uniform layer of liquid or flowable material. The system includes a distributor unit from which droplets of the material can be propelled by centrifugal force, and means are provided for spinning the distributor unit at relatively high rpms. The distributor unit includes a cylindrical chamber into which flowable material is received for distribution therefrom and the cylindrical chamber includes annular channels associated with spaced rows of openings which penetrate the wall of the cylindrical chamber. The system is especially useful for coating lining compounds or interior surfaces of pipes.
U.S. Pat. No. 4,499,118 shows a method of applying a coating of atomizable material to the inside surface of a glass tube comprising positioning a rotatable member within the tube, delivering the material to a surface of the member adapted to receive the material, and rotating the member at a predetermined velocity to atomize the material and impact the surface of the tube with at least a portion of the atomized material. A potential difference may be established between the atomized material and the surface of the tube to improve coating efficiency. The surface of the tube may be maintained at an electrical potential, and multiple coatings may be produced.
U.S. Pat. No. 5,141,774 discloses an apparatus for coating the inner wall or surface of hollow objects utilizing centrifugal force to apply fluid to the object. A probe is moved from underneath the object thereby utilizing gravitational forces to prevent spillage of the material from the probe. A computer controls the pumping rate, the vertical movement of the probe and the rotational speed of the probe to allow the machine to precisely coat a band on the internal cavity of an article.
U.S. Pat. No. 3,327,681 is directed to a improved boom mounting and rotary head for application of uniform coating of epoxy resins paints or other suitable coating material to tubular members. A rotary head drive and control unit are secured to the forward end of a stabilizing unit. The boom serves as a conduit for air lines, hydraulic and electrical control lines as well as the line for carrying the coating material to the rotary head. The various controls are mounted within the rotary head drive and control unit including a constant torque variable speed hydraulic motor which is coupled to drive the rotary head unit provided on the forward end of the drive and control unit. The speed of the motor is regulated through a flow control valve which is mounted on the hydraulic power unit located adjacent to the machine.
FR 2 305 245 shows an apparatus to apply enamel to the internal tube wall by a projector operating during the extrusion process. The projector is a variable speed rotary disc on the mandrel to which the enamel is delivered.
The present invention is directed to the device used to deliver the lining or coating of cement to the interior of the pipe. As a length of iron pipe moves through the foundry line, a slinger head is positioned in the pipe to deliver the cement. The slinger head is hollow with openings through which the cement is forced under centrifugal force. An air source is used to spin the slinger head as it moves the length of the pipe spraying cement on the prior pipe wall.